Fig. 5: Cytochrome bd-deficient biofilm cells have elevated uptake of noxious chemicals. | npj Biofilms and Microbiomes

Fig. 5: Cytochrome bd-deficient biofilm cells have elevated uptake of noxious chemicals.

From: Cytochrome bd promotes Escherichia coli biofilm antibiotic tolerance by regulating accumulation of noxious chemicals

Fig. 5

a Volcano plot depicting all outer membrane or secreted proteins detected by LC-MS/MS performed on outer membrane and extracellular matrix extracts. Blue dots represent outer membrane channel proteins. b Heatmap depicting the relative difference in abundance of outer membrane proteins in UTI89 and ∆cydAB. Each cell contains fold difference in abundance relative to UTI89. OmpA and LamB did not attain statistical significance. Data in a, b are representative of three biological replicates per strain. c–e RT-qPCR was performed to determine the relative fold difference in outer membrane protein transcript abundance normalized to gyrB abundance between UTI89 and ∆cydAB in samples derived from homogenized colony biofilms grown on YESCA agar for 11 days (c) and planktonic cells (d). e Difference in outer membrane protein transcript abundance between ∆cydAB biofilm and planktonic cells was evaluated by comparing the abundance of each transcript to gyrB abundance. Data in c–e are representative of four biological replicates and were analyzed using a two-tailed unpaired t-test. f Cellular uptake of membrane impermeant ethidium bromide into planktonic cells and cells extracted from homogenized biofilms. Data are representative of at least six biological replicates and were analyzed by a two-tailed unpaired t-test. g Cellular uptake of resazurin-based dye PrestoBlue into planktonic cells (solid lines) and cells extracted from homogenized biofilms (dashed lines) was quantified over time. Data were fit to a linear regression model and analyzed by statistically comparing the slope. Data are representative of at least three biological replicates. h Percent difference in PrestoBlue uptake at 60 min in ∆cydAB cells as compared to UTI89. Data were analyzed with a two-tailed unpaired t-test. Except where noted all data are presented as mean ± SEM, and each dot represents a biological replicate. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.

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